25.1 + 25.2 Vibrations are wiggles in time. Waves are vibrations, but they are also a wiggle in space along with time. The time of one swing of a pendulum are called the period. A period depends on the length and the gravitational force; (the longer the pendulum, the slower the period.) Simple Harmonic Motion- the back and forth motion of a pendulum.
A wave always has a Sine curve. the top of a way is called crests and a low point is called troughs. The distance between either the crests or troughs is called the wavelength. Frequency is how often the vibrations occur. Its measured in Hertz (Hz). 1 Hertz = 1 cycle per second. Frequency = 1/Period and vice versa.
25.3 - 25.6
Wavespeed depends on what it moves through. Wavespeed = frequency X wavelength. TransverseWaves- When the motion of the medium is at right angles to the direction in whice the wave travels. LongitudinalWaves- Particles move along the direction of the wave.
25.7- 25.8 Interference Patterns- when two waves overlap with eachother, they will either increase, decrease, or neutralize the waves. Constructive interference- when one crest of a wave of another wave overlaps the crest of another, the effects add together. DestructiveInterference- When one crest of a wave overlaps a trough of another wave and the effects cancel out.
If you take a rope and hold one end stationary and shake it up and down, it creates the incedent and reflecting waves form a standing wave.
On a standing wave, the stationary parts are called Nodes and the parts with the largest amplitudes are Antinodes.
Doppler Effect- The change in frequency due to the motion of the source. The greater the speed, the greater the doppler effect will be. Blue Shift- An increase in frequency. Its called that due to the increase towards high-frequencys or the blue end of the spectrum. Red Shift- A decrease in frequency. Its called that due to the decrease towards low-frequencys or the red end of the spectrum. http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/waves/u10l3d3.gif (Doppler effect)
Bow Waves- the crests that appear V-shaped due to the crests overlapping at the edges. Unlike a speedboat, which creates 2-D bow waves, a aircraft will create a Shock Wave, or a 3-D bow wave.
When the shell of compressed air from a high-speed plane reaches the listeners below, a sharp crack or Sonic Boom will be heard. http://www.aoe.vt.edu/~jschetz/fluidnature/unit10/unit10b.html (Bow wave) http://www.daviddarling.info/images/sonic_boom.jpg (Sonic boom)
25.1 + 25.2
Vibrations are wiggles in time. Waves are vibrations, but they are also a wiggle in space along with time. The time of one swing of a pendulum are called the period. A period depends on the length and the gravitational force; (the longer the pendulum, the slower the period.)
Simple Harmonic Motion- the back and forth motion of a pendulum.
A wave always has a Sine curve. the top of a way is called crests and a low point is called troughs. The distance between either the crests or troughs is called the wavelength.
Frequency is how often the vibrations occur. Its measured in Hertz (Hz). 1 Hertz = 1 cycle per second. Frequency = 1/Period and vice versa.
25.3 - 25.6
Wavespeed depends on what it moves through.
Wavespeed = frequency X wavelength.
Transverse Waves- When the motion of the medium is at right angles to the direction in whice the wave travels.
Longitudinal Waves- Particles move along the direction of the wave.
25.7- 25.8
Interference Patterns- when two waves overlap with eachother, they will either increase, decrease, or neutralize the waves.
Constructive interference- when one crest of a wave of another wave overlaps the crest of another, the effects add together.
Destructive Interference- When one crest of a wave overlaps a trough of another wave and the effects cancel out.
If you take a rope and hold one end stationary and shake it up and down, it creates the incedent and reflecting waves form a standing wave.
On a standing wave, the stationary parts are called Nodes and the parts with the largest amplitudes are Antinodes.
http://learn.uci.edu/media/OC08/11004/OC0811004_StandingWave02.jpg (Standing wave)
25.9 - 25.11
Doppler Effect- The change in frequency due to the motion of the source. The greater the speed, the greater the doppler effect will be.
Blue Shift- An increase in frequency. Its called that due to the increase towards high-frequencys or the blue end of the spectrum.
Red Shift- A decrease in frequency. Its called that due to the decrease towards low-frequencys or the red end of the spectrum. http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/waves/u10l3d3.gif (Doppler effect)
Bow Waves- the crests that appear V-shaped due to the crests overlapping at the edges.
When the shell of compressed air from a high-speed plane reaches the listeners below, a sharp crack or Sonic Boom will be heard.
http://www.daviddarling.info/images/sonic_boom.jpg (Sonic boom)
Mike Adams